The basic choices are black, white, green, and silver (Aluminet). All four physically block light transmission, by the mere presence of the mesh, but they also reflect some of the light, and that's the primary difference.
Black reflects very little, so with all four choices being of the same percentage open space, black provides the least transmission. Black, however, converts more of the absorbed light into heat than the others, so can affect the environment that way to a relatively significant degree. The light that gets through is pretty much unchanged spectrally from the source.
White reflects more than black, and absorbs less, so there is less heat generation. The light that reflects off of it into the growing environment carries all wavelengths and is very dispersed. Again, with no significant change to the spectrum.
The silvered Mylar that is Aluminet absorbs almost none of the light, doing most of its attenuation by reflection, so has the least amount of heat generation. Light reflected into the growing space will be very directional, and not well dispersed from any point, as is the case with white.
Colored shade cloths - focusing on green, specifically - will generate less heat than the black material, but more than the others. The light that is reflected into the growing environment will be fairly well dispersed, but is also narrowed in its spectrum, so can definitely have an impact on the growth of the plants. In the case of green, while it may be used by the plant to produce energy pumped into photosynthesis, it is not used directly in that process, so is probably overall less efficient than allowing the unaltered spectrum through.
Personally, I recommend the Aluminet, as its lack of heat generation may allow you to decrease the shading percent, thereby giving more energy to the plants. White is my second choice, while I'd avoid green altogether.
Ray Barkalow
Sent using Tapatalk
Last edited by Ray; 04-05-2013 at 10:25 AM..
|
Linear Mode
